Fig. 2. The cells responsive to DC5 activity in Drosophila are the cone cells. The activity pattern of DC5(8x) in the adult compound eye (A) and in the larval eye imaginal disc (B) was compared with the activity pattern of the cone-cell-specific enhancer SME (C,D). SME is the minimal eye-specific enhancer of D-Pax2 (Flores et al., 2000). Fluorescence microscopy indicates that both activity patterns are identical, as shown in preparations of the larval eye imaginal disc (E,F,G) and in cryosections of the adult compound eye (H,I,J). When a signal-peptide-tagged EGFP was used as a reporter for the enhancer activity, the fluorescence signal was detected in the lenses of the compound eye (K). This experiment was done in a w⁺ genetic background to keep the ommatidium structure unaltered (L).